The West Australian division of the Liberal Party says there is a real chance a Queenslander campaigning on cannabis law reform could end up representing WA in the Senate.

The Palmer United Party (PUP) has preferenced the Help End Marijuana Prohibition (HEMP) Party lead candidate James Moylan 14th, ahead of the Liberals and all other WA-based candidates of major parties.

The comments come just 10 days out from the WA senate re-run after last September's result was declared void by the Court of Disputed Returns.

The Liberals have described the situation as "Senate madness" and say it shows neither PUP nor the HEMP Party are interested in what is best for West Australians.

"I just think that Western Australians need to understand the opportunism, the crassness of what is going on here," WA Liberal Senator David Johnston said.

"These people are Johnny-come-latelies, they have no sentiment for Western Australia.

"The minor party distribution of preferences is so complex, so fraught with danger and risk, that I just want to stand here and say, 'for goodness' sake, just stick with the Liberals'."

Greens candidate may face bigger threat from HEMP

Political analyst William Bowe says it is possible Mr Moylan could take a WA Senate spot.

"I wouldn't say [it's] likely, but the thing with the Senate is practically anything can happen," he said.